The present invention generally relates to a robotic mechanism for use in an apparatus for preparing dishes using recipe steps and cooking conditions coded as a computer program recipe executed by a kitchen top robotic cooking machine supplied with the required ingredients with minimal user intervention while adjusting recipe to tastes of the user.
A need exists for a robotic mechanism for use in automated home cooking machines as disclosed in U.S. Pat. No. 9,131,807. Gantry robots with three or more axes disclosed in prior art such as U.S. Pat. No. 8,973,768 are serial mechanism and each axis carries the next one. The first gantry axis such as x-axis is driven by an actuator in combination with a linear motion device such as ball screw driven by a motor or integrated as in a linear motor, the actuator and motion elements for the second axis such as y-axis are mounted onto the first axis or x-axis and all elements of the y-axis move along x-axis, further more a third axis such as a z-axis is made possible by similar actuator and linear motion devices by attaching them to the y-axis firmly. So for any x-motion the actuators and mechanism for y and z axis move along x-axis and for any y-axis motion all elements of z-axis move along the y-direction. So only the motor for first axis is stationary and the rest of the actuators or motors are in constant motion. This requires all the power cables and encoder feedbacks cables are carried as well and flexible to allow changing shapes due to changing positions between connected cable ends. Constant motion can cause cables and motors to fail eventually and increasing the cost with reduced reliability.
Further the user can be exposed to the hazardous voltages being carried to the second and third motors by fatigue failure of cable insulations due to stress fatigue or attack from corrosive elements in workspace. Cable design and management is a very critical aspect of such robotic mechanisms. Having to carry secondary axes also creates additional force and strength requirement from the primary axes requiring overdesign for primary axes.
A need exists for a robot that is able to meet the needs of a cooking machine that is used in a harsh environment as in the case of household cooking where the robot mechanism is exposed to various unsuitable conditions such as heat, moisture, grease, fumes, acids and bases. Further the robot needs to be reliable for use for long periods of times without requiring any servicing in a home user environment as compared to an industrial environment where regular daily, weekly, monthly and annual preventive maintenance and inspections are common. The robot also needs to be safe for average users not familiar with industrial machinery. The robot needs to be able to carry weights ranging from light to relatively heavy for its size. Electrical cables and connections should not be exposed to cooking environment such as high temperatures, moisture, fumes, grease and other particulate material as this can cause their gradual degradation as well as electrical shock and fire hazards caused by compromised insulation. Furthermore an industrial robot with cables and motors moving around are not a welcome sight for a consumer device.
Further a need exists for a robot that has positioning precision suitable for a consumer application for home cooking by transporting ingredients and intermediates efficiently but cost effective at the same time. The positioning accuracy and overall functionally should not be impacted by the operating conditions such as temperatures and moisture. The robot mechanism must be compact to be able to fit in a conventional kitchen and of comparable size to a home appliance. The robot also needs to provide continuous operation without need for periodic servicing as in case of industrial robots. The robot should have safety features to coexist with members of a household including children. The robot mechanism should allow it to be design compatible with government food preparation and health standards and keep industrial machinery components such as lubricants, hazardous design materials away from the operation area.
A need therefore exists to provide a robot that can be used for a consumer food preparation device which can survive the harsh conditions over long periods of time. The electrical systems and drives can be located such that they are remote from the food preparation areas and are not accessible to the user. There are no moving cables or electrical power delivery components including electrical connections exposed to the cooking environment. The electrical systems and drives are safety isolated from the average customer but can be accessed and serviced by qualified technicians. The robot mechanism providing a large number or controlled degrees of freedom as needed for three dimensional positioning, tilting and gripping utilizing fewer motors and controlled axis to be cost effective for a consumer application.